1. Field of the Invention
The present invention pertains to solid state relay circuits, and more particularly, it pertains to relay circuits of the impulse-sequence type wherein successive triggering pulses cause the relay to toggle between its activated and unactivated conditions.
2. Description of the Prior Art
With the advent of thyristor devices of high current carrying capabilities, such as the SCR and the triac, a considerable variety of solid state relay circuits have been devised to provide switching functions formerly provided by electromechanical relays. There has not been readily available, however, a solid state relay circuit of the impulse-sequence or ratchet-impulse type where successive triggering impulses cause the relay to change its state. Problems are encountered in designing such a circuit to handle available triggering impulse signals and yet be relatively free from noise and other mistriggering problems. Furthermore, such circuits must be capable of high speed switching operation with both resistive and inductive loads.